Johann Christian Doppler whose name is so frequently honoured in modern-day technology was so little regarded by his colleagues that we know relatively little about his personality. One of his biographers describes him as humble and hard-working but he responded to the criticisms of Buys Ballot in a rather stubborn fashion and apparently his mathematic was not faultless. The only likeness we have of him (Fig. 1) is a bust set up by the University of Vienna in 1901 but it is not known how true it is to life. His career, like the early history of the effect he described and which is named after him, was checkered. He was born in Salzburg in 1805 (Fig. 2) and was the son of a master stone mason. Apparently he had some talent as a carver but did not have the physique to follow this craft. As a result of the interest of the mathematician Stampfer he was sent to the Polytechnic Institute of Vienna but after graduation he was unable to obtain a good position. He got as far as Munich on his way to emigrate to America when he was appointed Professor of Mathematics and Accounting at the State Secondary School in Prague in 1835. In 1841 he became Professor of Elementary Mathematics and Practical Geometry at the State Technical Academy in Prague and it was in this position that he wrote his famous paper entitled “On the Coloured Light of Double Stars and Some other Heavenly Bodies” (Fig. 3). The paper was given before the Royal Bohemian Society of Learning in 1842 and published in 1843. In 1847 he became Professor of Mathematics, Physics and Mechanics at the Mining Academy at Schemnitz at which time he was given an honorary doctorate by Charles University in Prague. However, he had to return to Vienna because of the industrial troubles and in 1850 he received his only prestigious appointment as Director of the new Physical Institute which had been founded for the training of teachers and became a full Professor of Experimental Physics at the Royal Imperial University of Vienna which was the first such appointment to be made in Austria. Unfortunately he had developed pulmonary troubles while in Prague which resulted in his death in Vienna shortly afterwards in 1853 at the early age of 49. It should be noted that many of the difficulties encountered in the early acceptance of the Doppler effect resulted from the fact that he worked under rather isolated circumstances since no other important physicists were working in Bohemia or Austria in the early part of the 19th century. Doppler’s famous paper begins by recapitulating the wave theory of light and explaining that the colour perceived by the eye varies with the frequency. He went on to postulate that this frequency will increase if the observer is moving towards the source and decrease if he is moving away from the source and drew an analogy of a ship moving to meet or retreat from a train of ocean waves. He went on to deduce in rather clumsy mathematical fashion the relationship:

Johann Christian Doppler and his effect—A brief history

Few specialties have a longer or richer eponymous background than obstetrics and gynaecology. Eponyms add a human side to an increasingly technical profession and represent the historic tradition and language of the speciality. This collection aims to perpetuate the names and contributions of pioneers and offer introductory profiles to the founders in whose steps we follow. This third edition includes 26 new entries, as well as expanded detail, illustration and quotation for existing entries. Biographical data and historical and medical context are discussed for each of the 391 names, with reference to 34 countries, reflecting the field's far reaching origins. More than 1700 original references feature, alongside an extensive bibliography of more than 2500 linked references to assist readers searching for more detailed information. This is a volume for physicians, midwives, medical historians, medical ethicists and all those interested in the history and evolution of obstetrical and gynaecological treatment.

Eponyms and Names in Obstetrics and Gynaecology

Analysis of the signals, spectra and error bounds for Doppler ultrasound signals is challenging and involves numerous concepts in signal analysis, probability, acoustics, and fluid mechanics. Nonetheless, the results of this analysis must be accessible to both engineers and clinicians who work with ultrasound technology. The engineer who designs, builds, or maintains equipment must know whether specific artifacts are fundamental or can be eliminated. The clinician must be able to interpret whether specific signal features accurately represent the flow field or result from limitations of Doppler ultrasound. This article reviews recent advances in both conceptual and numerical models of the Doppler ultrasound process, and relates these advances to practical aspects such as spectral broadening, velocity estimation error, and data analysis error. It then reviews recent innovations in system implementation and signal analysis which are indicative of the future potential of Doppler ultrasound instrumentation.

Fundamental sources of error and spectral broadening in Doppler ultrasound signals

Limited-diffraction beams have a large depth of field and could be applied to medical imaging, tissue characterization, and nondestructive evaluation of materials. This paper reports the application of limited-diffraction beams, specifically, the Bessel beam, to Doppler velocity estimation. The Bessel beam has the advantage that velocity estimation is less subject to the depth of moving objects and the Doppler spectrum has distinct shoulders that increase the accuracy of velocity (both magnitude and Doppler angle) estimation in noisy environments. The shoulders of the Doppler spectrum might also help in solving the inverse problem, e.g., estimation of the velocity distribution in vessels. >

E.J. Jonkman

Papers

Doppler research in the nineteenth century.